An “electronic oscillator” includes a resonant circuit designed to produce a periodic, time-varying electrical signal of a given frequency—the inverse of the resonant circuit's period determines its frequency. The electrical signal may be used, for instance, to keep track of the passage of time by counting a number of signal oscillations. A common electronic oscillator employs a quartz crystal as its resonating element, although other types of piezoelectric materials (e.g., polycrystalline ceramics) may also be used.
In certain applications, a “clock generator” may use an electronic oscillator to produce a “clock signal.” The clock signal may in turn enable one or more Integrated Circuits (ICs) or the like to synchronize or otherwise coordinate their various operations. Generally speaking, a clock generator has a resonant circuit and an amplifier. The resonant circuit acts as a highly selective band-pass filter that allows only a small range of frequencies to pass through it without much attenuation (other frequencies are essentially filtered out). The amplifier then feeds the resulting periodic signal back into the resonant circuit to maintain its oscillation.